45, COBNHILL, E.G., AND 122, BEGENT STREET, W., LONDON. 109 



small tube of the syphon, or the long leg ; and the whole contents of the reser- 

 voir, 6r, immediately run off, and the spiral springs 6 &, elevate the reservoir to 

 its original position. To produce this action, a quarter of an inch of rain must 

 have fallen. The registration is easily understood. A spring lever, z, carrying 

 a pencil, is attached by a cord, c, to S. This spring always keeps the cord 

 tight, so that as the apparatus descends during the fall of rain, the spring 

 advances the pencil more and more from the zero of the scale upon the paper 

 beneath, until a quarter of an inch has fallen, when the pencil is drawn back to 

 zero by the ascent of the reservoir. 



The registration trace for twenty-four hours is readily understood. The 

 direction is recorded on the centre part ; the pressure on one side, and the rain 

 on the other. Lines parallel to the length of the paper show no rain, steady 

 wind, and constant pressure. On the rain-trace, a line parallel to the width of 

 the paper, shows that the pencil had been drawn back to zero, a quarter of an 

 inch of rain having fallen. The hour lines are in the direction of the width of 

 the paper. 

 Price, for Osier's Self-registering Anemometer and Rain Gauge, fig. 117, from 84 to 150. 



150. Beckley's Anemometer. Mr. R. Beckley, of the Kew Observatory, 

 has devised a self-registering anemometer, which consists of three principal 

 parts : Robinson's cups for the determination of velocity ; a double fan, or 

 windmill governor, for obtaining the direction ; and a clock to move a cylinder, 

 around which registration paper is wrapped. The paper records the time, 

 velocity, and direction of the wind for twenty-four hours, when it must be 

 replaced. It has a cast-iron tubular support, or pedestal, to carry the external 

 parts the cups and the fan, which must be erected upon the roof of the 

 building upon which it is desired to mount the instrument. 



The fans keep their axis at right angles to the wind ; and with any change 

 of direction they move, carrying with them an outer brass tube, which rests 

 upon friction balls on the top of the pedestal, and is attached to a tubular shaft 

 passing through the interior of the pedestal, and terminating with a mitre 

 wheel. The mitre wheel, working with other cogged wheels, communicates 

 the motion of the direction shaft to a cylinder carrying a pencil, to record the 

 direction. 



The shaft carrying the cups is supported upon friction balls, placed in a 

 groove formed on the top of the direction shaft, and passing through the 

 interior of that shaft, comes out below the mitre wheel, where it is terminated 

 in an endless screw, or worm. 



